Coating materials, method for their production and use of said materials

ABSTRACT

Coating materials, processes for preparing them, and their use. The coating materials include hydroxyl-containing (meth)acrylate (co)polymer, carbamate and hydroxyl-functional compound, an amino resin, and a triazine compound. At least 10 equivalent % of the hydroxyl groups present in (A) and/or (B) are primary hydroxyl groups. The coating materials after curing have a storage modulus E′ in the rubber-elastic range of at least 1.5*10 7  Pa, the storage modulus E′ having been measured by dynamic mechanical thermoanalysis (DMTA) on homogeneous free films with a thickness of 40±10 μm.

FIELD OF THE INVENTION

The present invention relates to novel coating materials. The presentinvention also relates to a novel process for preparing coatingmaterials. The present invention further relates to the use of the novelcoating materials for producing coatings, adhesive films, seals,moldings and self-supporting films, preferably scratchproof coatings,more preferably scratchproof clearcoats, especially for scratchproofmulticoat paint systems.

PRIOR ART

In years gone by great advances have been made in the development ofacid-resistant and etch-resistant clearcoats for automotive OEMfinishing. In recent times an increased desire has now arisen on thepart of the automobile industry for scratchproof clearcoats which at thesame time retain the existing level in terms of their other properties.

International patent application WO 98/40442 discloses coating materialswhich lead to scratchproof coatings. These coating materials in thecured state have a storage modulus E′ of at least 10⁷ Pa. The coatingmaterials comprise as binders hydroxyl-functional (meth)acrylatecopolymers having a hydroxyl number of 100 to 240 mg KOH/g, an acidnumber from 0 to 35 mg KOH/g, a number-average molecular weight from1,500 to 10,000 daltons, and a glass transition temperature of not morethan 70° C., more preferably from −40 to +30° C. The hydroxyl-functional(meth)acrylate copolymers ought to contain as many primary hydroxylgroups as possible. More preferably at least 50 to 100% of the hydroxylgroups present are primary hydroxyl groups. Crosslinking agents used areamino resins, tris(alkoxycarbonylamino)triazines and/or polyisocyanates.The use of compounds containing at least one carbamate group and atleast one hydroxyl group is not described. The coatings produced fromthe known coating materials possess high scratch resistance, high gloss,good chemical resistance, and good weathering stability. The etchresistance, on the other hand, leaves something to be desired.Furthermore, it is necessary to improve the chemical resistance stillfurther in order to satisfy the heightened requirements of the market.

European patent application EP 0 675 141 A1 discloses a coating materialwhose binder is a methacrylate copolymer with a number-average molecularweight of 3,071 daltons, containing primary hydroxyl groups andcarbamate groups, and whose crosslinking agent is an amino resin. Thebinder is comparatively viscous, and for that reason the coatingmaterial is comparatively difficult to apply. Although the coatingproduced from it has a high gloss, its etch resistance, hardness andimpact strength leave much to be desired.

In order to improve the level of properties of this known coatingmaterial and of the coating produced from it, EP 0 675 141 A1 proposesusing as binder (meth)acrylate copolymers which contain carbamate groupsand sterically hindered secondary hydroxyl groups. It is true that thesebinders may also contain primary hydroxyl groups. As is apparent fromthe examples of the European patent application, however, binderscontaining no primary hydroxyl groups are preferred. These binders havea comparatively low viscosity, and so the coating materials in questionare easier to apply. The coatings produced from them possess goodchemical resistance, etch resistance, hardness, and impact strength, andalso a high gloss. Indications as to the scratch resistance, however,are lacking.

European patent application EP 0 915 113 A1 discloses coating materialscomprising as binders (i) compounds such as (meth)acrylate copolymerscontaining hydroxyl groups and carbamate groups or (ii) compounds suchas (meth)acrylate copolymers containing hydroxyl groups and (iii) acompound containing carbamate groups, and, as crosslinking agents,polyisocyanates and amino resins.

The (meth)acrylate copolymers (ii) have a number-average molecularweight of from 1,000 to 40,000 and a glass transition temperature offrom −20 to +80° C. and contain preferably primary hydroxyl groups (cf.EP 0 915 113 A1, page 5, lines 9 and 10 and page 6, lines 10 to 13).

The compounds (iii) containing carbamate groups may also containhydroxyl groups, the ratio of hydroxyl to carbamate groups beingunspecified. They can also be used as binders (i). Whether and, if so,to what extent the hydroxyl-containing compounds (iii) might also beused in combination with the (meth)acrylate copolymers (ii) is notapparent from EP 0 915 113 A1.

According to the examples of EP 0 915 113 A1 it is preferred to use(meth)acrylate copolymers (iii) containing secondary hydroxyl groups andcarbamate groups as binders on their own. Thus, for example, themethacrylate copolymer of example 1 has a carbamate equivalent weightCEW of 493 g/equivalent and a hydroxyl equivalent weight of 493g/equivalent. Data on number-average molecular weight and glasstransition temperature are absent. The multicoat paint systems producedwith the aid of the coating material have a good etch resistance buttheir scratch resistance leaves much to be desired.

European patent EP 0 994 930 B 1 discloses coating materials comprising(meth)acrylate copolymer binders containing primary and secondaryhydroxyl groups. The (meth)acrylate copolymers have a number-averagemolecular weight of from 5,000 to 25,000, a hydroxyl equivalent weightof from 300 to 800 g/equivalent and a glass transition temperature of atleast +10° C. The (meth)acrylate copolymers may also contain anunspecified number of carbamate groups. The combination of thecarbamate-free (meth)acrylate copolymers with compounds containingcarbamate groups is as little apparent from the patent as the ratio ofhydroxyl to carbamate groups. Amino resin crosslinking agents are used.In addition, polyisocyanates and/or tris(alkoxycarbonylamino)triazines(TACT) may be used as further crosslinking agents.

The coatings produced from the known coating materials are intended onthe one hand to have the durability, hardness, gloss and overall opticalappearance normally possessed by the coatings produced from coatingmaterials based on hydroxyl-containing (meth)acrylate copolymers andamino resins and on the other hand to have the etch resistance normallypossessed by the coatings produced from coating materials based onhydroxyl/isocyanate, epoxy/acid, and carbamate/amino resin crosslinkingsystems. The scratch resistance and the chemical resistance,particularly the motor fuel resistance, of these known coatings,however, continues to leave much to be desired.

According to European patent EP 1 042 402 B 1 the scratch resistance andabrasion resistance of the coatings produced from the coating materialsknown from European patent EP 0 994 930 B1 are improved by addingtris(alkoxycarbonylamino)triazines (TACT) to the coating materials asadditional crosslinking agents. However, the known coatings do notattain the scratch resistance which must be attained in order thatdamage no longer occurs to the coatings in practice in car washinstallations.

PROBLEM ADDRESSED BY THE INVENTION

It is an object of the present invention to provide coating materialswhich no longer have the disadvantages of the prior art but whichinstead are stable on storage and easy and convenient to apply.Following application and curing, the novel coating materials shouldproduce coatings which combine a particularly high scratch resistancewith very good chemical resistance and etch resistance, particularly inthe pancreatin, tree resin, and gasoline tests, and very goodappearance.

Furthermore, the coatings should be resistant in particular towardconcentrated sulfuric acid and oil soot and should possess a highyellowing resistance.

Not least, the novel coating materials should be suitable for producingcoatings, adhesive films, and seals, preferably scratchproof coatings,more preferably scratchproof clearcoats, especially scratchproofmulticoat paint systems for the automotive sector.

SOLUTION PROVIDED BY THE INVENTION

The invention accordingly provides the novel coating materials,comprising

-   (A) at least one hydroxyl-containing (meth)acrylate (co)polymer    having a hydroxyl number of from I00 to 250 mg KOH/g, an acid number    of from 0 to 35 mg KOH/g, a number-average molecular weight M_(n) of    from 1,200 to 20,000 daltons, and a glass transition temperature of    not more than +70° C.,-   (B) at least one carbamate- and hydroxyl-functional compound having    a hydroxyl number of from 10 to 150 mg KOH/g, a carbamate equivalent    weight CEW of from 250 to 700 g/equivalent and an equivalents ratio    of hydroxyl to carbamate groups of from 1:20 to 1:0.5,-   (C) at least one amino resin, and-   (D) at least one compound of the general formula    in which the variable R stands for an alkyl group having 1 to 12    carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or an    aryl group having 6 to 20 carbon atoms and the variable X stands for    a nitrogen, oxygen or sulfur atom;    where-   (I) at least 10 equivalent % of the hydroxyl groups present in the    (meth)acrylate (co)polymers (A) and/or the compounds (B) are primary    hydroxyl groups and-   (II) the coating materials after curing have a storage modulus E′ in    the rubber-elastic range of at least 1.5*10⁷ Pa, the storage modulus    E′ having been measured by dynamic mechanical thermoanalysis (DMTA)    on homogeneous free films with a thickness of 40±10 μm.

The novel coating materials are referred to below as “coating materialsof the invention”. The invention also provides a novel process forpreparing coating materials, in which

-   (A) at least one hydroxyl-containing (meth)acrylate (co)polymer,-   (B) at least one compound containing carbamate groups and hydroxyl    groups,-   (C) at least one amino resin, and-   (D) at least one compound of the general formula    -   in which the variable R stands for an alkyl group having 1 to 12        carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or        an aryl group having 6 to 20 carbon atoms and the variable X        stands for a nitrogen, oxygen or sulfur atom        are mixed with one another and the resulting mixture is        homogenized, the constituents of the coating materials being        selected such that-   (I) at least 10 equivalent % of the hydroxyl groups present in the    (meth)acrylate (co)polymers (A) and/or the compounds (B) are primary    hydroxyl groups and-   (II) the coating materials after curing have a storage modulus E′ in    the rubber-elastic range of at least 1.5*10⁷ Pa, the storage modulus    E′ having been measured by dynamic mechanical thermoanalysis on    homogeneous free films with a thickness of 40+10 μm.

The novel process for preparing coating materials is referred to belowas “process of the invention”.

Further subject matters of the invention will become apparent from thedescription.

THE ADVANTAGES OF THE INVENTION

In the light of the prior art it was surprising and unforeseeable forthe skilled worker that the object on which the present invention wasbased could be achieved by means of the coating materials of theinvention and by means of the process of the invention.

In particular it was surprising that the coating materials of theinvention produced coatings, particularly clearcoats for multicoat paintsystems on motor vehicle bodies, which were distinguished simultaneouslyby high scratch resistance and by a high level of resistance topancreatin, tree resin, and gasoline, especially FAM standard test motorfuel (50% by volume toluene, 30% by volume isooctane, 15% by volumediisobutylene, 5% by volume ethanol). The test known as the FAM test iscarried out in accordance with VDA [German Automakers' Association] testbulletin 621-412 (based on DIN standard 53 168). Furthermore, thecoatings of the invention were hard, highly glossy,condensation-resistant, and of high yellowing resistance and adhesivestrength.

It was also surprising that the coating materials of the invention weresuitable as adhesives and sealants for producing adhesive films andseals and also as starting products for producing self-supporting filmsand moldings.

The adhesive films, seals, self-supporting films and moldings of theinvention likewise had outstanding performance properties.

DETAILED DESCRIPTION OF THE INVENTION

It is critical to the invention that the coating materials and/or theirconstituents are selected such that the cured coating material has astorage modulus E′ in the rubber-elastic range, i.e., an energycomponent (elastic component) which is recoverable in the deformation ofa viscous elastic material such as a polymer, for example, of at least1.5*10⁷ Pa, preferably of at least 5*10⁷ Pa, more preferably of at least8*10⁷ Pa, very preferably of at least 10*10⁷ Pa, and with particularpreference of at least 14*10⁷ Pa, the storage modulus E′ having beenmeasured by dynamic mechanical thermoanalysis (DMTA) on homogeneous freefilms with a thickness of 40±10 μm.

DMTA is a widely known measurement method for determining the viscouselastic properties of coatings and is described, for example, inMurayama, T., Dynamic Mechanical Analysis of Polymeric Materials,Elsevier, N.Y., 1978 and Loren W. Hill, Journal of Coatings Technology,Vol. 64. No. 808, May 1992, pages 31 to 33. The process conditions aredescribed in detail by Th. Frey, K.-H. Grosse Brinkhaus and U. Röckrathin Cure Monitoring of Thermoset Coatings, Progress in Organic Coatings27 (1996), 59-66 or in German patent application DE 44 09 715 A1 or inGerman patent DE 197 09 467 C2.

The storage modulus E′ is measured on homogeneous free films. The freefilms are produced conventionally by applying the coating material inquestion to substrates and curing it, the substrates being those towhich the coating produced does not adhere. Examples that may bementioned of suitable substrates include glass, Teflon, and, inparticular, polypropylene. Polypropylene has the advantage of readyavailability and is therefore normally used as support material.Preference is given to employing the following conditions: tensile mode;amplitude: 0.2%;

frequency: 1 Hz; temperature ramp: 1° C./min from room temperature to200° C.

The measurements can be conducted, for example, with the instruments MKII, MK III or MK IV from the company Rheometric Scientific.

The specific selection of the coating materials by way of the value ofthe storage modulus E′ in the rubber-elastic range at 20° C. of thecured coating materials makes it possible in a simple way to providecoating materials having the desired good scratch resistance, since theparameter can be determined by means of simple DMTA measurements.

The energy component consumed (dissipated) in the deformation of theviscous elastic material is described by the size of the loss modulusE″. The loss modulus E″ is likewise dependent on the rate of deformationand the temperature. The loss factor tanδ is defined as the quotientformed from the loss modulus E′ and the storage modulus E′. tanδ canlikewise be determined with the aid of DMTA and represents a measure ofthe relationship between the elastic and plastic properties of the film.The loss factor tanδ may vary; preferably at 20° C. it is not more than0.10, preferably not more than 0.06.

The value of the storage modulus E′ can be controlled by way of theselection of the binders and crosslinking agents.

For example, the storage modulus increases as the hydroxyl number of thebelow-described binders (A) and (B) overall goes up and as the carbamateequivalent weight CEW of component (B) goes down and as the proportionof primary hydroxyl groups in the below-described binders (A) and (B)goes up.

The coating materials of the invention comprise at least onehydroxyl-containing (meth)acrylate (co)polymer (A) having a hydroxylnumber of from 100 to 250, preferably from 160 to 220, and morepreferably from 170 to 200 mg KOH/g, an acid number of from 0 to 35 andpreferably from 0 to 25 mg KOH/g, a glass transition temperature of notmore than +70° C. and preferably from −40° C. to +70° C., and anumber-average molecular weight of from 1,200 to 20,000, preferably from1,500 to 15,000 and more preferably from 1,500 to 10,000 daltons. It isimportant that the hydroxyl content of the (meth)acrylate (co)polymer(A) or (B) is chosen so that at least 10%, preferably at least 15%, andmore preferably at least 20 equivalent % of the hydroxyl groups presentin (A) and/or (B) are primary hydroxyl groups. With particularpreference the primary hydroxyl groups originate predominantly, inparticular substantially completely, from component (A). In principle,all (meth)acrylate (co)polymers (A) having the stated characteristics(hydroxyl number, acid number, glass transition temperature andnumber-average molecular weight) are suitable provided that they lead,after crosslinking, to coatings having the stated viscous elasticparameters.

The glass transition temperature can be calculated approximately by theskilled worker with the aid of the formula$\frac{1}{T_{g}} = {\sum\limits_{1}^{i}\frac{W_{i}}{T_{g,i}}}$

T_(g)=glass transition temperature of the polymer

i=number of different copolymerized monomers

W_(i)=weight fraction of the ith monomer

T_(g,i) =glass transition temperature of the homopolymer of the ithmonomer.

The coating materials are prepared using, for example, methacrylatecopolymers (A1) obtainable by copolymerizing

-   (a1) from 10 to 51% by weight, preferably from 20 to 45% by weight,    of 4-hydroxy-n-butyl acrylate or 4-hydroxy-n-butyl methacrylate or a    mixture of 4-hydroxy-n-butyl acrylate and 4-hydroxy-n-butyl    methacrylate,-   (b1) from 0 to 36% by weight, preferably from 0 to 20% by weight, of    a hydroxyl-containing ester of acrylic acid or a hydroxyl-containing    ester of methacrylic acid, other than (a1), or of a mixture of such    monomers,-   (c1) from 28 to 58% by weight, preferably from 34 to 50% by weight,    of an aliphatic or cycloaliphatic ester of (meth)acrylic acid having    at least 4 carbon atoms in the alcohol residue, other than (a1) and    (b1), or of a mixture of such monomers,-   (d1) from 0 to 3% by weight, preferably from 0 to 2% by weight, of    an ethylenically unsaturated carboxylic acid or of a mixture of    ethylenically unsaturated carboxylic acids, and-   (e1) from 0 to 40% by weight, preferably from 5 to 35% by weight, of    a vinylaromatic and/or of an ethylenically unsaturated monomer other    than (a1), (b1), (c1), and (d1), or of a mixture of such monomers,    the sum of the weight fractions of components (a1), (b1), (c1), (d1)    and (e1) always being 100% by weight.

The preferred glass transition temperature of this methacrylatecopolymer (A1) is from −40 to +70° C.

The coating materials are also prepared using, for example, methacrylatecopolymers (A2) obtainable by copolymerizing

-   (a2) from 10 to 51% by weight. preferably from 20 to 45% by weight,    of a hydroxyl-containing methacrylate, preferably hydroxypropyl    methacrylate or hydroxyethyl methacrylate, or a mixture of such    monomers, preferably a mixture of hydroxypropyl methacrylate and    hydroxyethyl methacrylate,-   (b2) from 0 to 36% by weight, preferably from 0 to 20% by weight, of    a hydroxyl-containing ester of acrylic acid or a hydroxyl-containing    ester of methacrylic acid, other than (a2), or of a mixture of such    monomers,-   (c2) from 28 to 58% by weight, preferably from 34 to 50% by weight,    of an aliphatic or cycloaliphatic ester of (meth)acrylic acid having    at least 4 carbon atoms in the alcohol residue, other than (a2) and    (b2), or of a mixture of such monomers,-   (d2) from 0 to 3% by weight, preferably from 0 to 2% by weight, of    an ethylenically unsaturated carboxylic acid or of a mixture of    ethylenically unsaturated carboxylic acids, and-   (e2) from 0 to 40%, preferably from 5 to 35% by weight, of a    vinylaromatic and/or of an ethylenically unsaturated monomer other    than (a2), (b2), (c2), and (d2), or of a mixture of such monomers,    the sum of the weight fractions of components (a2), (b2), (c2), (d2)    and (e2) always being 100% by weight.

The preferred glass transition temperature of this methacrylatecopolymer (A2) is 10 from −40 to ±70° C.

The (meth)acrylate (co)polymers (A) used with preference in accordancewith the invention, especially the methacrylate copolymers (A1) and(A2), can be prepared by polymerization methods which are well andgenerally known. Polymerization methods for preparing polyacrylateresins are common knowledge and have been described in many instances(cf. e.g. Houben-Weyl, Methoden der organischen Chemie, 4^(th) Edition,Volume 14/1, pages 24 to 255 (1961)).

The (meth)acrylate (co)polymers (A) used with preference in accordancewith the invention are prepared in particular with the aid of thesolution polymerization method. In this case usually an organic solventor solvent mixture is introduced as an initial charge, which is heatedto boiling. The monomer mixture to be polymerized, together with one ormore polymerization initiators, is then added continuously to thisorganic solvent or solvent mixture. The polymerization takes place attemperatures between 100 and 160° C., preferably between 130 and 150° C.polymerization initiators used are preferably initiators which form freeradicals.

The type and amount of initiator are normally chosen so that the supplyof free radicals during the feed phase at the polymerization temperatureis very largely constant.

Examples of initiators which can be used include the following: dialkylperoxides, such as di-tert-butyl peroxide and dicumyl peroxide;hydroperoxides, such as cumene hydroperoxide and tert-butylhydroperoxide; peresters, such as tert-butyl perbenzoate, tert-butylperpivalate, and tert-butyl per-2-ethylhexanoate; and bisazo compoundssuch as azobisisobutyronitrile.

The polymerization conditions (reaction temperature, feed time of themonomer mixture, amount and type of organic solvents and polymerizationinitiators, possible use of molecular weight regulators, such asmercaptans, thioglycolates, and hydrogen chlorides) are selected suchthat the polyacrylate resins used with preference have a number-averagemolecular weight of from 1,200 to 20,000, preferably from 1,500 to15,000, more preferably from 1,500 to 10,000 (determined by gelpermeation chromatography using a polystyrene standard).

The acid number of the (meth)acrylate (co)polymers (A) used inaccordance with the invention can be set by the skilled worker usingappropriate amounts of carboxyl-functional monomers. The same applies tothe setting of the hydroxyl number, which can be controlled by way ofthe amount of hydroxyl-functional monomers used.

As component (a1) it is possible to use 4-hydroxy-n-butyl acrylate,4-hydroxy-n-butyl methacrylate or a mixture of 4-hydroxy-n-butylacrylate and 4-hydroxy-n-butyl methacrylate. In one preferred embodimentthe component (a1) used is 4-hydroxy-n-butyl acrylate.

As component (a2) it is possible to use hydroxyalkyl esters ofmethacrylic acid, particularly those in which the hydroxyalkyl groupcontains up to 8, preferably up to 6, and more preferably up to 4 carbonatoms, or mixtures of these hydroxyalkyl esters. Examples of suchhydroxyalkyl esters include 2-hydroxypropyl methacrylate,3-hydroxypropyl methacrylate and 2-hydroxyethyl methacrylate.

As component (b1) and, respectively, (b2) it is possible in principle touse any hydroxyl-containing ester of acrylic acid or methacrylic acidother than (a1) or (a2), or a mixture of such monomers. Examples of (b1)and (b2) include the following: hydroxyalkyl esters of acrylic acid,such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,3-hydroxypropyl acrylate or 3-hydroxybutyl acrylate and hydroxyalkylesters of methacrylic acid, such as hydroxyethyl methacrylate andhydroxypropyl methacrylate, and also the esterification products ofhydroxyalkyl (meth)acrylates with one or more molecules ofε-caprolactone. Al so suitable are reaction products of acrylic and/ormethacrylic acid with a glycidyl ester. Glycidyl esters can be obtainedby reacting a monofunctional carboxylic acid (e.g., octanoic acid,benzoic acid, benzilic acid, cyclohexanoic acid) with an epihalohydrin(e.g., epichlorohydrin) under the known reaction conditions. Glycidylesters are available commercially, for example, as Cardura® E fromShell, Glydexx® N-10 from Exxon or Araldit® PT910 from Ciba. Glycidylesters may be represented by the following formula:

in which R is a substituted or unsubstituted hydrocarbon radical having1 to 40, preferably 1 to 20, and more preferably 1 to 12 carbon atoms.Polyglycidyl esters may likewise be used and are preparable by reactinga polyfunctional carboxylic acid (e.g. phthalic acid, thioglycolic acid,adipic acid) with an epihalohydrin. Polyglycidyl esters may likewise berepresented by the above formula. In this case, R is substituted by oneor more glycidyl ester groups. Preference is given to using thecommercial products sold under the brand name Cardurao®, Glydeex® orAraldit®.

As component (c1) and, respectively, (c2) it is possible in principle touse any aliphatic or cycloaliphatic ester of (meth)acrylic acid havingat least 4 carbon atoms in the alcohol residue, other than (a1) or (a2)and (bl) or (b2), or a mixture of such monomers. Examples include thefollowing: aliphatic esters of (meth)acrylic acid with 4 to 20 carbonatoms in the alcohol residue, such as n-butyl, iso-butyl, tert-butyl,2-ethylhexyl, stearyl and lauryl methacrylate, and cycloaliphatic estersof (meth)acrylic acid such as cyclohexyl methacrylate, for example.

As component (d1) or (d2) it is possible in principle to use anyethylenically unsaturated carboxylic acid or a mixture of ethylenicallyunsaturated carboxylic acids. As component (d1) or (d2) it is preferredto use acrylic acid and/or methacrylic acid.

As component (e1) or (e2) it is possible in principle to use anyethylenically unsaturated monomer other than (a1) or (a2), (b1) or (b2),(c1) or (c2) and (d1) or (d2), or a mixture of such monomers. Examplesof monomers which can be used as component (e1) or (e2) include thefollowing: vinylaromatic hydrocarbons, such as styrene, α-alkylstyreneand vinyltoluene, amides of acrylic acid and methacrylic acid, such asmethacrylamide and acrylamide; nitriles of methacrylic acid and acrylicacid; vinyl ethers and vinyl esters. As component (e) it is preferred touse vinylaromatic hydrocarbons, especially styrene.

The coating materials of the invention comprise at least one compound B)which bears carbamate groups and hydroxyl groups.

The compound B) has a hydroxyl number of from 10 to 150, preferably from15 to 120, and more preferably from 20 to 100 and a carbamate equivalentweight CEW of from 250 to 700, preferably from 300 to 600, morepreferably from 350 to 500, and with very particular preferance from 360to 450.

The ratio of hydroxyl groups to carbamate groups in the compound B) isfrom 1:20 to 1:0.5, preferably from 1:15 to 1:0.8, and more preferablyfrom 1:10 to 1:1.

Carbamate groups can be obtained in various ways. It is possible, forexample, to react cyclic carbonate groups, epoxy groups, and unsaturatedbonds to form carbamates.

Cyclic carbonate groups can be converted to carbamate groups by reactingthem with ammonia or primary amines, with the ring of the cycliccarbonate group being opened and a β-hydroxyl carbamate being formed.

Epoxy groups can be converted into carbamate groups by reacting themfirst with CO₂ to form a cyclic carbonate, after which the furtherreaction can then take place as outlined above. The reaction with CO₂can take place at pressures between atmospheric pressure andsupercritical CO₂, it being preferred to carry out the reaction undersuperatmospheric pressure (e.g., from 400 to 1050 kPa). The temperaturefor carrying out this reaction is preferably between 60 and 150° C.Catalysts which can be used when carrying out this reaction are thosewhich activate an oxirane ring, such as tertiary amines or quaternarysalts (e.g., tetramethylammonium bromide), combinations of complexorganotin halides and alkylphosphonium halides (e.g., (CH₃)₃SnI,(C₄H₉)₃SNI, Bu4PI and (CH₃)₄PI), potassium salts (e.g., K₂CO₃, KI)preferably in combination with crown ethers, tin octoate, calciumoctoate, and the like.

Unsaturated bonds can be converted to carbamates by reacting them firstwith peroxide to give epoxides, then with CO₂ to give cyclic carbonates,and thereafter with ammonia or primary amines to give carbamates.

The carbamate may be primary, i.e., ending in an NH₂ group, orsecondary, i.e., ending in an NHR group where R is an organic radical.In a preferred embodiment the carbamate is primary. Another way toobtain compounds (B) is to react an alcohol (an alcohol being a compoundbearing one or more hydroxyl groups) with more than one urea compound inorder to obtain a compound which bears carbamate groups. This reactionis carried out with heating of a mixture of alcohol and urea. It ispreferred to add a catalyst.

Another possibility is the reaction of an alcohol with cyanic acid(HOCN) to produce a compound having primary carbamate groups.

Carbamates may likewise be obtained by reacting an alcohol with phosgenefollowed by a reaction with ammonia, giving compounds having primarycarbamate groups, or they can be obtained by reacting an alcohol withphosgene followed by reaction with a primary amine, in which casecompounds having secondary carbamate groups result.

A further way is to react an isocyanate (e.g., HDI, IPDI) with acompound such as hydroxypropyl carbamate to give a carbamate-blockedisocyanate derivative.

Introducing the carbamate group into the compound B) can also be done,if compound B) is a polymer, by incorporating monomers which containcarbamate groups. Examples of suitable monomers of this kind areethylenically unsaturated monomers which contain a carbamate group.

One possibility is to prepare a (meth)acrylic monomer having a carbamatefunction in the ester moiety of the monomer. Such monomers are known andare described in, for example, American patents U.S. Pat. No. 3,479,328A, U.S. Pat. No. 3,674,838 A, U.S. Pat. No. 4,126,747 A, U.S. Pat. No.4,279,833 A and U.S. Pat. No. 4,340,497 A.

Further methods of obtaining the monomers are known to the skilledworker and may likewise be employed.

The acrylic monomer, together where appropriate with other ethylenicallyunsaturated monomers, can then be (co)polymerized by methods which arecommon knowledge.

Alternatively, the carbamate group may be introduced into the compoundB) by means of polymer-analogous reactions. Examples of suitable methodsof this kind are known from patents U.S. Pat. No. 4,758,632 A, U.S. Pat.No. 4,301,257 A or U.S. Pat. No. 2,979,514 A.

One possibility of preparing carbamate-functional polymers by apolymer-analogous route is to carry out thermal cleavage of urea in thepresence of a hydroxyl-functional (meth)acrylate (co)polymer (in orderto liberate ammonia and HNCO), which then gives a carbamate-functional(meth)acrylate (co)polymer.

It is likewise possible to react the hydroxyl group of a hydroxyalkylcarbamate with the isocyanate group of an isocyanate-functional acrylicor vinylic monomer to give a carbamate-functional component.Isocyanate-functional (meth)acrylates are known and are described in,for example, U.S. Pat. No. 4,301,257 A. Isocyanate-functional vinylmonomers are likewise known and include olefinically unsaturatedm-tetramethylxylene isocyanate (available under the name TMI® fromAmerican Cyanamid).

Yet another possibility is to react cyclic carbonate groups of a polymercontaining such groups with ammonia in order to form a polymer whichcontains carbamate groups. Polymers containing cyclic carbonate groupsare likewise known and are described in, for example, U.S. Pat. No.2,979,514 A.

A somewhat more complicated but likewise possible route to thepreparation of polymers containing carbamate groups is thetransesterification of a (meth)acrylate (co)polymer with a hydroxyalkylcarbamate.

Also conceivable is the preparation of the compounds (B) by the reactionof hydroxyl-containing polymers with phosgene and subsequently withammonia, as described in, for example, DE 199 46 048 and DE 101 29 969.

A preferred route, however, is to react an existing polymer, such as a(meth)acrylate (co)polymer, for example, with another component in orderto attach a carbamate group to the existing polymer backbone, as isdescribed in, for example, U.S. Pat. No. 4,758,632 A.

Carbamates can be obtained with preference by polymer-analogoustranscarbamation. In this case an alcohol is caused to react with analkyl carbamate (e.g., methyl carbamate, ethyl carbamate, butylcarbamate) to give a compound containing primary carbamate groups. Thisreaction is carried out with heating, preferably in the presence of acatalyst, such as organometallic catalysts (e.g., dibutyltin dilaurate).

Further possibilities for the preparation of carbamates are known to theskilled worker and are described in, for example, P. Adams F. Baron,“Esters of Carbamic Acid”, Chemical Review, v. 65, 1965.

In the preparation of these compounds (B) it should be ensured, in thecase of subsequent introduction of the carbamate group, for example,that both hydroxyl groups and carbamate groups are present in sufficientnumber in the final compound (B).

Compound (B) is preferably polymeric.

Suitable polymers (B) come from the polymer classes of the random,alternating and/or block, linear and/or branched and/or comb, addition(co)polymers of ethylenically unsaturated monomers, or polyadditionresins and/or polycondensation resins. For further details of theseterms refer to Rompp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,Stuttgart, New York, 1998, page 457, “Polyaddition” and “Polyadditionresins (Polyadducts)”, and also pages 463 and 464, “Polycondensates”,“Polycondensation”, and “Polycondensation resins”.

Examples of highly suitable addition (co)polymers (B) are (meth)acrylate(co)polymers and partially hydrolyzed polyvinyl esters, especially(meth)acrylate (co)polymers.

Examples of highly suitable polyaddition resins and/or polycondensationresins (B) are polyesters, alkyds, polyurethanes, polylactones,polycarbonates, polyethers, epoxy resin-amine adducts, polysiloxanes,polyureas, polyamides or polyimides, especially polyesters.

With very particular preference the polymers (B) come from the polymerclasses of (meth)acrylate (co)polymers.

Processes for preparing the carbamate-functional polymers (B) which comefrom the aforementioned polymer classes are known from patentapplications

-   -   EP 0 675 141 B1, page 2 line 44 to page 5 line 15 and page 8        line 5 to page 10 line 41, and    -   EP 0 915 113 A1, Example 1, page 11 lines 3 to 15.

The polymers (B) are preferably prepared by copolymerizing a monomermixture comprising at least one olefinically unsaturated carboxylicacid, methacrylic acid for example, in the presence of a glycidyl esterof Versatic® acid (cf. Römpp Lexikon Lacke und Druckfarben, Georg ThiemeVerlag, Stuttgart New York, 1998 “Versatic® Acids”, pages 605 and 606)and then reacting the resultant hydroxyl-containing (meth)acrylate(co)polymer with at least one alkyl carbamate, such as methyl, propyl,or butyl carbamate.

As compound (B) consideration may also be given to a (meth)acrylatecopolymer (B1) obtainable by copolymerizing

-   (a) from 10 to 50%, preferably from 10 to 40% by weight, more    preferably from 20 to 30% by weight of a hydroxyl-containing    (meth)acrylate or of a mixture of such monomers,-   (b) from 0 to 50% by weight, preferably from 10 to 40% by weight, of    a monomer containing at least one carbamate group, the carbamate    group being a reaction product of an epoxide and an acid with    subsequent reaction of the resultant hydroxyl group to form    carbamate, or of a mixture of such monomers,-   (c) from 5 to 58% by weight, preferably from 5 to 45% by weight, of    an aliphatic or cycloaliphatic ester of (meth)acrylic acid having at    least 4 carbon atoms, preferably at least 6 carbon atoms, in the    alcohol residue, other than (a) and (b), or of a mixture of such    monomers,-   (d) from 0 to 3% by weight, preferably from 0 to 2% by weight, of an    ethylenically unsaturated carboxylic acid or of a mixture of    ethylenically unsaturated carboxylic acids and-   (e) from 0 to 40% by weight, preferably from 5 to 35% by weight, of    an ethylenically unsaturated monomer other than (a), (b), (c), and    (d), or of a mixture of such monomers,    the sum of the weight fractions of components (a), (b), (c), (d)    and (e) always being 100% by weight.

The equivalents ratio of hydroxyl groups to monomer containing carbamategroups in this (meth)acrylate copolymer (B1) is preferably from 1:0.5 to1:0.9.

Components (a), (c), (d) and (e) here correspond to the componentsalready described above for the (meth)acrylate (co)polymers (A).

Component (b) is a monomer containing at least one carbamate group, thecarbamate group being a product of the reaction of an epoxide and anacrylically unsaturated acid with subsequent reaction of the resultanthydroxyl group to carbamate, or a mixture of such monomers.

Alternatively it is preferred to prepare a (meth)acrylate (co)polymer(B) from components (a) to (e), where component

-   (b) is from 0 to 50% by weight, preferably from 10 to 40% by weight,    of a monomer which itself is a reaction product of an epoxide and an    acid    and then, in the resulting (meth)acrylate (co)polymer, to react the    hydroxyl group resulting from the reaction of an epoxide and an acid    of component (b) with an alkyl carbamate.

It is preferred if the alkyl carbamate used is methyl carbamate.

In one preferred embodiment the epoxide is a monoepoxide, preferably anepoxy ester, such as one of the glycidyl esters described above.

The epoxides described are reacted with an unsaturated, acid-functionalcompound in order to open the oxirane ring. Here it is possible, forexample, to use acrylic acid and/or methacrylic acid.

The compounds (b) contain an α,□-ethylenically unsaturated organicradical by way of which they can be polymerized into the (meth)acrylate(co)polymer. The epoxide can be reacted before, during or after thepolymerization. Where this reaction takes place during or after thepolymerization, appropriate measures, which are common knowledge, mustbe taken to ensure that even after the reaction the resultant(meth)acrylate (co)polymer (B) contains hydroxyl groups and carbamategroups in sufficient number.

The ratio of all hydroxyl groups from constituents (A) and (B) to thecarbamate groups from the compound (B) is preferably from 1:10 to 1:0.5,more preferably from 1:5 to 1:0.5, and with very particular preferencefrom 1:2 to 1:1.

The oligomers and polymers (B) preferably have a number-averagemolecular weight of from 600 to 20,000, preferably from 800 to 15,000,more preferably from 1,000 to 10,000, with very particular preferencefrom 1,200 to 8,000, and in particular from 1,200 to 6,000 daltons.

The coating materials used in the process for producing scratchproofcoatings comprise amino resins (C) as crosslinking agents.

These resins (C) are condensation products of aldehydes, especiallyformaldehyde, with, for example, urea, melamine, guanamine andbenzoguanamine. The amino resins contain alcohol groups, preferablymethylol groups, which in general are partly or, preferably, fullyetherified with alcohols. Use is made in particular ofmelamine-formaldehyde resins etherified with lower alcohols,particularly with methanol or butanol. Very particular preference isgiven to using as crosslinking agents melamine-formaldehyde resins whichare etherified with lower alcohols, especially with methanol and/orethanol and/or butanol, and which on average still contain from 0.1 to0.25 nitrogen-bonded hydrogen atoms per triazine ring.

In this context it is possible to use any amino resins suitable fortransparent topcoat or clearcoat materials, or a mixture of such resins.Particularly suitable are the conventional amino resins, some of whosemethylol and/or methoxymethyl groups have been deftnctionalized by meansof carbamate or allophanate groups.

Crosslinking agents of this kind are described in patents U.S. Pat. No.4,710,542 A and EP 0 245 700 B1 and also in the article by B. Singh andCoworkers, “Carbamylmethylated Melamines, Novel Crosslinkers for theCoatings Industry” in Advanced Organic Coatings Science and TechnologySeries, 1991, Volume 13, pages 193 to 207. On the melamine resinsreference may also be made to Rompp Lexikon Lacke und Druckfarben, 1988,pages 374 and 375, “Melamine resins” and to the book “Lackadditive”[Additives for Coatings] by Johan Bieleman, 1988, pages 242 to 250,section on “Melamine-resin-crosslinking systems”.

It is particularly preferred here if the crosslinking agent (C) is richin melamine resin; that is accordingly is a melamine resin or aminoresin mixture with a melamine resin fraction of at least 60% by weight,preferably at least 70% by weight, in particular at least 80% by weight,based in each case on the amino resin mixture.

Melamine resins are well known to the skilled worker and are supplied bynumerous companies as sales products:

Examples of suitable, low molecular mass, fully etherified melamineresins are Cymel® 301 and 303 from Cytec, Luwipal® 066 from BASFAktiengesellschaft, Resimene® and Maprenal® MF from Solutia.

Examples of suitable, comparatively low molecular mass, highlyetherified melamine resins containing free imino groups are Cymel® 325and 327 (methanol-etherified) and 1158 (butanol-etherified) from Cytec,Luwipale® 062 (methanol-etherified), 018 (butanol-etherified), and 014(butanol-etherified, of relatively high viscosity) from BASFAktiengesellschaft, Maprenal® MF 927 and 3950 (methanol-etherified), VMF3611 and 3615 (butanol-etherified) and 580 (isobutanol-etherified), andalso Resimene® 717 and 718 (methanol-etherified), and 750 and 5901(butanol-etherified), and also MB 9539 from Solutia and Setamine® US 138and US 146 (butanol-etherified) from Akzo Resins.

Examples of suitable, comparatively low molecular mass, partiallyetherified melamine resins are Luwipal® 012, 016, 015 and 010 from BASFAktiengesellschaft, Maprenal® MF 590 and 600 from Solutia and Setamine®US 132 and 134 from Akzo Resins.

The coating materials of the invention comprise at least one compound ofthe general formula:

in which the variable R stands for an alkyl group having 1 to 12 carbonatoms, a cycloalkyl group having 3 to 12 carbon atoms or an aryl grouphaving 6 to 20 carbon atoms, in particular for an alkyl group having 1to 8 carbon atoms, and the variable X stands for a nitrogen, oxygen orsulfur atom, in particular an oxygen atom, as crosslinking agent(s) (D).

Accordingly, the tris(alkoxycarbonylamino)triazines are especiallysuitable crosslinking agents (D). Examples of particularly suitabletris(alkoxycarbonyl-amino)triazines (D) are described in patents U.S.Pat. No. 4,939,213A, U.S. Pat. No. 5,084,541 A, and EP 0 624 577 A1. Useis made in particular of the tris(methoxy-, tris(butoxy- and/ortris(2-ethylhexoxycarbonylamino)triazines. Of advantage are themethyl-butyl mixed esters, the butyl-2-ethylhexyl mixed esters, and thebutyl esters. They have the advantage over the straight methyl ester ofbetter solubility in polymer melts, and also tend less towardcrystallization.

The weight ratio of crosslinking agent (C) to crosslinking agent (D) mayvary widely and is guided by the requirements of the case in hand.Preferably, the weight ratio (C):(D) is from 40:1 to 1:1, morepreferably from 30:1 to 1:1, with particularpreference from 20:1 to 1:1and inparticular from 10:1 to 1.2:1.

The coating materials of the invention may where appropriate comprise atleast one further crosslinking agent, (E), other than the amino resins(C) and (D). Agents (E) are selected from the group consisting ofconventional crosslinking agents which crosslink with the hydroxylgroups of (A) and/or (B) and, in doing so, form ethers and/or esters,such as anhydrides, for example, and/or the conventional blocked and/ornonblocked polyisocyanates, as are described, for example, in Germanpatent application DE 199 14 896 A1. Where blocked polyisocyanates (E)are present the coating materials of the invention are one-componentsystems.

Where nonblocked polyisocyanates (E) are used the coating materials ofthe invention are two-component systems.

The amount of the above-described essential constituents (A) and (B) inthe coating materials of the invention may vary widely and is guided bythe requirements of the case in hand, in particular by the functionalityof complementary reactive groups in components (A) and (B) on the onehand and the crosslinking agents (C) and (D) on the other. The amount ofthe binders (A)+(B) is preferably from 30 to 80%, more preferably from35 to 75%, with particular preference from 40 to 70% with veryparticular preference from 45 to 65% and in particular from 50 to 60% byweight, based in each case on the solid of the composition of theinvention; the amount of the crosslinking agents (C)+(D) is preferablyfrom 20 to 70%, more preferably from 25 to 65%, with particularpreference from 30 to 60%, with very particular preference from 35 to55%, and in particular from 40 to 50% by weight, based in each case onthe solid of the composition of the invention.

Furthermore, the coating materials of the invention may also comprise atleast one conventional additive (F) selected from the group consistingof binders other than the above-described binders (A) and (B),especially hydroxyl-containing binders;

reactive diluents; molecularly dispersipbly soluble dyes; lightstabilizers, such as UV absorbers and reversible free-radical scavengers(HALS); antioxidants; low-boiling and high-boiling (“long”) organicsolvents; devolatilizers; wetting agents; emulsifiers; slip additives;polymerization inhibitors; crosslinking catalysts; adhesion promoters;leveling agents; film-forming auxiliaries; Theological aids, such asthickeners and pseudo-plastic sag control agents, SCAs; flameretardants; corrosion inhibitors; free-flow aids; waxes; siccatives;biocides; and flatting agents.

Examples of suitable additives (F) are described in detail in thetextbook “Lackadditive” by Johan Bieleman, Wiley-VCH, Weinheim, NewYork, 1998, in D. Stoye and W. Freitag (Editors), “Paints, Coatings andSolvents”, second, completely revised edition, Wiley-VCH, Weinheim, NewYork, 1998, “14.9. Solvent Groups”, pages 327 to 373.

The coating materials of the invention comprising the constituentsdescribed above are used in particular as clearcoat materials forproducing clearcoats or as starting products for the production ofclear, transparent self-supporting films and moldings.

Alternatively, the coating materials of the invention may be pigmented.In that case they preferably comprise at least one conventional pigment(G) selected from the group consisting of organic and inorganic,transparent and opaque, color and/or effect, electrically conductive,magnetically shielding and fluorescent pigments, fillers, andnanoparticles.

The pigmented coating materials of the invention are used in particularas electrocoat materials, surfacers, basecoat materials and solid-colortopcoat materials for producing electrocoats, surfacer coats orantistonechip primer coats, basecoats and solid-color topcoats, or forproducing pigmented self-supporting films and moldings.

Where exclusively nonopaque pigments (G) are used, especiallynanoparticles, the pigmented coating materials of the invention may alsobe used as clearcoat materials or for producing clear, transparentself-supporting films and moldings.

In terms of method, the preparation of the coating materials of theinvention has no particular features but instead takes place by mixingand homogenizing the above-described constituents using conventionalmixing techniques and apparatus such as stirred tanks, stirrer mills,extruders, compounders, Ultraturrax, inline dissolvers, static mixers,micromixers, toothed-wheel dispersers, pressure release nozzles and/ormicrofluidizers. It is essential here, however, to select theconstituents of the coating materials of the invention such that, afterthey have been cured, the coating materials of the invention have theabove-described, DMTA-determined mechanical-dynamic properties.

The resultant coating materials of the invention are, in particular,conventional coating materials comprising organic solvents. However,they may also be aqueous compositions, substantially or completelysolvent-free and water-free liquid compositions (100% systems),substantially or completely solvent-free and water-free solid powders orsubstantially or completely solvent-free powder suspensions (powderslurries).

The coating materials of the invention are applied to conventionaltemporary or permanent substrates. For producing self-supporting filmsand moldings of the invention it is preferred to use conventionaltemporary substrates, such as metal belts and polymer belts or hollowbodies made of metal, glass, plastic, wood or ceramic, which can easilybe removed without damaging the self-supporting films and moldings ofthe invention.

Where the coating materials of the invention are used for producingcoatings, adhesive films and seals, permanent substrates are used, suchas motor vehicle bodies and parts thereof, the interior and exterior ofbuildings and parts thereof, doors, windows, furniture, hollowglassware, coils, freight containers, packaging, small parts, electricalcomponents, and components for white goods. The self-supporting filmsand moldings of the invention may likewise serve as substrates. Furtherexamples of suitable substrates are known from German patentapplications DE 199 24 172 A1, page 8 lines 21 to 37 or DE 199 30 067A1, page 13 line 61 to page 14 line 16.

In terms of method, the application of the coating materials of theinvention has no special features but can instead take place by anyconventional application method suitable for the composition inquestion, such as, for example, electrocoating, spraying, squirting,knifecoating, brushing, flowcoating, dipping, trickling or rolling. Itis preferred to employ spray application methods, unless thecompositions in question are powders.

The application of the powders does not have particular features interms of method either but instead takes place, for example, inaccordance with the conventional fluid-bed methods, such as are known,for example, from the BASF Coatings AG brochures “Pulverlacke fuirindustrielle Anwendungen”, January 2000, or “Coatings Partner,Pulverlack Spezial”, 1/2000, or from Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, pages 187and 188, “Electrostatic Powder Spraying”, “Electrostatic Spraying” and“Electrostatic Fluid-Bath Process”.

The coating materials of the invention are used preferably for producingmoldings and self-supporting films or as coating materials, adhesives,and sealants for producing coatings, adhesive films and seals. Inparticular, the coating materials are used for producing multicoat colorand/or effect paint systems by the conventional wet-on-wet methods (cf.,for example, German patent applications DE 199 14 896 A1, column 16 line54 to column 18 line 57, and DE 199 30 067 A1, page 15 line 25 to page16 line 36).

The curing of the applied coating materials of the invention likewisehas no special features in terms of method but instead takes place withthe aid of the conventional methods, such as thermally in particular,for example by heating in a forced-air oven or irradiation with IRlamps.

The coating compositions of the invention are used preferably forproducing multicoat paint systems or in processes for producingmulticoat paint systems, in that case preferably as topcoat material,particularly in the area of automotive OEM finishing. The presentinvention accordingly further provides a process for producing multicoatpaint systems, in which

-   -   (1) a pigmented basecoat material is applied to the substrate        surface,    -   (2) from the basecoat material a polymer film is formed,    -   (3) a transparent topcoat material is applied to the resulting        basecoat film, and then    -   (4) the basecoat film and topcoat film are cured together,    -   which comprises using a coating composition of the invention in        at least one of the coating films. In this process it is        preferred to use a coating composition of the invention as        topcoat material.

In stage (1) of the process of the invention it is possible in principleto use all pigmented basecoat materials which are suitable for producingtwo-coat paint systems. Basecoat materials of this kind are well knownto the skilled worker. Not only water-thinnable basecoat materials butalso those based on organic solvents can be used. Suitable basecoatmaterials are described, for example, in U.S. Pat. No. 3,639,147 A1, DE33 33 072 A1, DE 38 14 853 A1, GB 2 012 191 A, U.S. Pat. No. 3,953,644A1, EP 0 260 447 A1, DE 39 03 804 A1, EP 0 320 552 A1, DE 36 28 124 A1,U.S. Pat. No. 4,719,132 A1, EP 0297 576 A1, EP 0 069 936 A1, EP 0 089497 A1 , EP 0 195 931 A1, EP 0 228 003 A1, EP 0 038 127 A1 and DE 28 18100 A1. These patent documents are also a source of further informationon the basecoat/clearcoat process in question.

The resultant coatings and self-supporting films of the invention,particularly the single-coat or multicoat color and/or effect paintsystems and clearcoats of the invention, especially the clearcoats, areeasy to produce and have outstanding optical properties (appearance) andvery high light stability, chemical resistance, water resistance,condensation resistance, weathering stability, and etch resistance. Inparticular they are free from turbidity and inhomogeneity. They have anoutstanding scratch resistance and abrasion resistance in combinationwith an outstanding surface hardness and acid resistance. Surprisinglythe coatings, especially the clearcoats, when exposed to the realisticAMTEC test, oNIy suffer a difference in gloss before and after exposureof less than 35, preferably less than 30, and in particular less than 25units, which underlines their particularly high scratch resistance.

The adhesive films of the invention join a wide variety of substratesfirmly and durably to one another and have a high chemical andmechanical stability even under conditions of extreme temperature and/ortemperature fluctuation.

Similarly, the seals of the invention seal the substrates permanentlyand exhibit a high chemical and mechanical stability even underconditions of extreme temperature and/or temperature fluctuation andeven in conjunction with exposure to aggressive chemicals.

Accordingly, the primed or unprimed substrates that are commonlyemployed in the technology fields addressed above and which have beencoated with at least one coating of the invention, bonded with at leastone adhesive film of the invention, sealed with at least one seal of theinvention and/or wrapped or packaged with at least one self-supportingfilm of the invention or at least one molding of the invention combine aparticularly advantageous profile of performance properties with aparticularly long service life, which makes them particularly attractiveboth economically and environmentally.

EXAMPLES Preparation Example 1

The Preparation of a Methacrylate Copolymer (A) A laboratory reactorwith a useful volume of 4 1, equipped with a stirrer, two droppingfumnels for the monomer mixture and initiator solution respectively, anitrogen inlet pipe, thermometer, and reflux condenser, was charged with601 g of an aromatic hydrocarbons fraction having a boiling range from158° C. to 172° C. The solvent was heated to 140° C. When 140° C. hadbeen reached, a monomer mixture of 225.4 g of styrene, 169 g of n-butylmethacrylate, 293 g of cyclohexyl acrylate, 225.4 g of hydroxypropylmethacrylate, 202.8 g of 2-hydroxyethyl methacrylate and 11.2 g ofacrylic acid was metered into the reactor at a uniform rate over thecourse of 4 hours and an initiator solution of 112.6 g of t-butylperethylhexanoate in 40 g of the aromatic solvent described was meteredinto the reactor at a uniform rate over the course of 4.5 hours. Themetering of the monomer mixture and of the initiator solution wascommenced simultaneously. After the end of the initiator feed thereaction mixture was held at 140° C. for 2 hours more, then diluted with119.6 g of the aromatic solvent described, and subsequently cooled. Theresulting polymer solution had a solids content of 60% by weight(determined in a forced-air oven, 1 h at 130° C.). The methacrylatecopolymer had a hydroxyl number of 156 mg KOH/g, an acid number of 10 mgKOH/g, a number-average molecular weight of 1,700, and a glasstransition temperature of +65° C.

Preparation Example 2

The Preparation of a Methacrylate Copolymer (B) Containing Hydroxyl andCarbamate Groups

A laboratory reactor having a useful volume of 4, equipped with astirrer, two dropping funnels for the monomer mixture and initiatorsolution respectively, a nitrogen inlet pipe, thermometer, and refluxcondenser, was charged with 176.7 g of an aromatic hydrocarbons fractionhaving a boiling range from 158° C. to 172° C., 188.8 g of methylcarbamate and 345.9 g of Cardura® E-10 (glycidyl ester of Versatic®acid, from Shell Chemie). The solvent was heated to 140° C. After 140°C. had been reached, a monomer mixture of 312 g of hydroxyethylmethacrylate, 85.4 g of cyclohexyl methacrylate, 117.41 g of methacrylicacid and 59.6 g of the aromatic solvent described and an initiatorsolution of 73.9 g of azoisovaleronitrile in 36.7 g of xylene weremetered into the reactor at a uniform rate over the course of 1 hour.The reactor was furnished with a distillation bridge. Then a solution of2 g of dibutyltin oxide in 106 g of xylene was added and the mixture washeated to 135° C. It was held at 135° C. and methanol was distilled offcontinuously until a hydroxyl number of 90 mg KOH/g was reached(determined by titrimetry). Thereafter, excess methyl carbamate wasdistilled off under reduced pressure at 14° C. for a period of twohours. The resulting polymer solution was diluted with methoxypropanolto a solids content of 70% by weight (determined in a forced-air oven, 1h at 130° C.). The resin had a carbamate equivalent weight CEW of 440.The equivalents ratio of hydroxyl groups to carbamate groups was 1:1.4.

Preparation Example 3

The preparation of a rheological aid (SCA)

1.76 parts by weight of hexamethylene diisocyanate and 2.3 parts byweight of butyl acetate 98/100 were charged to a receiver. A reactorequipped with reflux condenser and cooling means for reactor andreceiver was charged with 91.7 parts by weight of the methacrylatecopolymer solution (A) from preparation example 1 and 2.24 parts byweight of benzylamine. The contents of the receiver were metered intothe reactor and the resulting mixture was circulated a number of timesthrough an inline dissolver, during which the temperature did not exceed40° C. The solution of the rheological aid was discharged from thereactor, and the lines were flushed with 2 parts by weight of butylacetate 98/100. The resulting solution of the rheological aid had asolids content of 60% by weight.

Examples 1 and 2

Preparation of the Clearcoat Materials 1 and 2

For example 1, 3.7 parts by weight of the methacrylate copolymersolution (A) from preparation example 1, 35.2 parts by weight of themethacrylate copolymer solution (B) from preparation example 2, 5.7parts by weight of Solvermol® 908 (commercial polyol from Cognis), 13.8parts by weight of the solution of the rheological aid from preparationexample 3, 16.7 parts by weight of a commercial etherified melamineresin (Resimene® BM 9539), 5 parts by weight of atris-(alkoxycarbonylamino)triazine (TACT) (51 percent strength organicsolution), 1.2 parts by weight of a blocked acid catalyst (Nacure® 5076from King Industries), 1.9 parts by weight of Tinuvin® 384 and 0.8 partby weight of Tinuvin® 123 (both light stabilizers from Ciba), 0.2 partby weight of Byk® 310 (commercial leveling assistant (silicone oil) fromByk Chemie), 11.5 parts by weight of Solventnaphtha®, 0.5 part by weightof dimethyldodecylamine, 4 parts by weight of butanol, 3 parts by weightof butyl glycol acetate and 3 parts by weight of xylene were mixedthoroughly. This gave the clearcoat material 1.

For example 2, example 1 was repeated, replacing 31.6 parts by weight ofthe methacrylate copolymer solution (B) from preparation example 2 with25.2 parts by weight thereof and replacing 5 parts by weight of TACT (51percent strength) with 10 parts by weight thereof. This gave theclearcoat material 2.

The clearcoat materials 1 and 2 were stable on storage and ofcomparatively low viscosity. Their electrical resistance wascomparatively low: clearcoat 1:220 kΩ; clearcoat 2: 190 kΩ. Accordingly,the clearcoat materials could be applied very effectively byelectrostatic means.

Free films were produced from the clearcoat materials 1 and 2, and thesefilms were analyzed by DMTA. As a measure of the crosslinkingdensity/scratch resistance, the storage modulus E′ in the rubber-elasticrange was ascertained: clearcoat materials 1 and 2: E′=2 x 10⁷ Pa. Theclearcoat materials were therefore outstandingly suitable for producingscratchproof coatings.

Examples 3 and 4

The Production of Multicoat Paint Systems Using the Clearcoat Materials1 and 2

For example 3, clearcoat material 1 was used.

For example 4, clearcoat material 2 was used.

The clearcoat materials 1 and 2 were each applied wet-on-wet to testpanels which had each been coated with a baked electrocoat and with anuncured aqueous basecoat film. The resulting aqueous basecoat films andclearcoat films were baked at 140° C. for 20 minutes to give test panelsfeaturing multicoat paint systems comprising in each case an aqueousbasecoat and a clearcoat.

In order to test

-   -   the hardness according to Buchholz (DIN 53153:1977-11) and TUKON        (Tukon® Microhardness Tester from Wilson-Wolpert-Shore        Instruments),    -   the scratch resistance by the Rotahub test and by the        Amtec-Kistler test (Amtec) using 1.5 g/l Sikron SH 200 ultrafine        quartz powder (cf. T. Klimmasch, T. Engbert, Technology        Conference, Cologne, DFO, Report volume 32, pages 59 to 66,        1997; the gloss to DIN 67530 is measured before and after        damage; measurement direction perpendicular to the direction of        scratching), and    -   the adhesion by the cross-cut test (DIN ISO 2409:1994-10) before        and after exposure to condensation climate testing (CC; DIN        50017:1982),        multicoat paint systems comprising a black aqueous basecoat        produced from a commercial black aqueous basecoat material from        BASF Coatings AG were used. The black basecoat was chosen since        it allowed optimum observation of changes in the appearance of        the multicoat paint systems in question, caused by mechanical        damage.

The results of the tests can be found in Table 1. TABLE 1 Hardness,scratch resistance, adhesion, and condensation resistance of themulticoat paint systems of Examples 3 and 4 Examples: Test method 3 4Hardness: Buchholz 80/83 77/87 TUKON 11.5 12.5 Scratch Resistance:Rotahub Test before exposure 91 92 after exposure 83 72 Δ gloss 8 20Amtec Test before exposure 91 92 after exposure 73 72 Δ gloss 18 20reflow (2 h/60° C.) 74 74 Δ gloss reflow 17 18 Adhesion: Cross-cut testbefore exposure 0.5 0.5 24 h after exposure 0.5 0.5 in CC testCondensation climate testing: blistering 1 h after amount 0 0 exposuresize 0 0 swelling slight slight

The results underscore the high gloss and high hardness, scratchresistance, adhesive strength and condensation resistance of themulticoat paint systems.

For testing in accordance with

-   -   the oil soot test according to General Motors GME 60403,    -   the sulfuric acid test according to General Motors GME 60409,        and    -   the FAM standard test fuel test (50% by volume toluene, 30% by        volume isooctane, 15% by volume diisobutylene, 5% by volume        ethanol, in accordance with VDA (German automakers association)        test bulletin 621-412, based on DIN standard 53 168), 15        multicoat paint systems were used which comprised a metallic        aqueous basecoat produced from the commercial aqueous basecoat        material Starsilber III from BASF Coatings AG.

The results can be found in Table 2. TABLE 2 Oil soot, sulfuric acid andtest fuel resistance of the multicoat paint systems of examples 3 and 4Examples: Test method 3 4 Oil soot test 120 h 8 8 (target = 8 after 144h): 144 h 8 8 168 h 8 8 Sulfuric acid test  48 h 8 6 (target = 8 after 72 h 6 2 72 h):  96 h 6 2 FAM standard test before exposure 0 0 fueltest: after exposure 0 0

The results underscore the high resistance of the multicoat paintsystems to oil soot, sulfuric acid and condensation.

To test the yellowing resistance, multicoat paint systems were usedwhich comprised a white aqueous basecoat produced from the commercialaqueous basecoat material CandyweiB from BASF Coatings AG. For theinvestigation the aqueous basecoat films and clearcoat films were bakedin one case at 140° C. for 20 minutes (series 1) and in one case at 160°C. for 30 minutes (series 2). The yellow values of the multicoat paintsystems from series 1 and 2 were determined by yellow-value colorimetryin accordance with the Cielab method. The following differences inyellow values were found: multicoat paint system of example 3: Δb=0.7;multicoat paint system of example 4: Δb =0.7. The results demonstratethe high yellowing resistance of the multicoat paint systems.

1. A coating material comprising: (A) at least one hydroxyl-containing(meth)acrylate (co)polymer having a hydroxyl number of from 100 to 250mg KOH/g, an acid number of from 0 to 35 mg KOH/g, a number-averagemolecular weight M_(n) of from 1,200 to 20,000 daltons, and a glasstransition temperature of not more than +70° C., (B) at least onecarbamate- and hydroxyl-functional compound having a hydroxyl number offrom 10 to 150 mg KOH/g, a carbamate equivalent weight CEW of from 250to 700 g/equivalent and an equivalents ratio of hydroxyl to carbamategroups of from 1:20 to 1:0.5, (C) at least one amino resin, and (D) atleast one compound of the general formula

in which the variable R stands for an alkyl group having 1 to 12 carbonatoms, a cycloalkyl group having 3 to 12 carbon atoms or an aryl grouphaving 6 to 20 carbon atoms and the variable X stands for a nitrogen,oxygen or sulfur atom; where (I) at least 10 equivalent % of thehydroxyl groups present in the (meth)acrylate (co)polymers (A) and/orthe compounds (B) are primary hydroxyl groups and (II) the coatingmaterial, after it has been cured, has a storage modulus E′ in therubber-elastic range of at least 1.5*10⁷ Pa, the storage modulus E′having been measured by dynamic mechanical thermoanalysis (DMTA) onhomogeneous free films with a thickness of 40±10 μm.
 2. The coatingmaterial as claimed in claim 1, wherein the glass transition temperatureof the (meth)acrylate (co)polymers (A) is from −40 to +70° C.
 3. Thecoating material as claimed in claim 1, wherein the (meth)acrylate(co)polymers (A) have a hydroxyl number from 160 to 220 mg KOH/g and/ora number-average molecular weight M_(n) of from 1,500 to 15,000 daltons.4. The coating material as claimed in claim 1, wherein the methacrylatecopolymers (A) are prepared by copolymerizing (a1) from 10 to 51% byweight of monomers selected from the group consisting of4-hydroxy-n-butyl acrylate, 4-hydroxy-n-butyl methacrylate and mixturesthereof, (b1) from 0 to 36% by weight of monomers selected from thegroup consisting of hydroxyl-containing esters of acrylic acid andhydroxyl-containing esters of methacrylic acid, each other than (a1),mixtures thereof, (c1) from 28 to 58% by weight of monomers selectedfrom the group consisting of aliphatic esters of (meth)acylic acidhaving at least 4 carbon atoms in the alcohol residue, andcycloaliphatic esters of (meth)acrylic acid having at least 4 carbonatoms in the alcohol residue, where each is other than (a1) and (b1),and mixtures of such monomers, (d1) from 0 to 3% by weight of compoundsselected from the group consisting of ethylenically unsaturatedcarboxylic acids and mixtures thereof, and (e1) from 0 to 40% by weightof monomers selected from the group consisting of vinylaromatic monomersand ethylenically unsaturated monomers each being other than (a1), (b1),(c1), and (d1), and mixtures thereof, the sum of the weight fractions ofcomponents (a1), (b1), (c1), (d1) and (e1) always being 100% by weight.5. The coating material as claimed in claims 1, wherein the methacrylatecopolymers (A) are prepared by copolymerizing (a2) from 10 to 51% byweight of monomer(s) selected from the group consisting of hydroxypropylmethacrylate and hydroxyethyl methacrylate, and mixtures there, (b2)from 0 to 36% by weight of monomers selected from the group consistingof hydroxyl-containing esters of acrylic acid and hydroxyl-containingester of methacrylic acid, each being other than (a2), and mixturesthereof, (c2) from 28 to 58% by weight of monomers selected from thegroup consisting of aliphatic esters and cycloaliphatic esters of(meth)acrylic acid having at least 4 carbon atoms in-the alcoholresidue, each being other than (a2) and (b2), and mixtures thereof, (d2)from 0 to 3% by weight of compounds selected from the group consistingof ethylenically unsaturated carboxylic acids and mixtures thereof, and(e2) from 0 to 40% by weight of monomers selected from the groupconsisting of vinylaromatic and ethylenically unsaturated monomerseachother than (a2), (b2), (c2), and (d2), and mixtures thereof, the sumof the weight fractions of components (a2), (b2), (c2), (d2) and (e2)always being 100% by weight.
 6. The coating material as claimed in claim1, wherein the compound (B) is a (meth)acrylate (co)polymer containinghydroxyl groups and carbamate groups.
 7. The coating material as claimedin claim 1, wherein the compound (B) has a hydroxyl number of from 15 to120 mg KOH/g.
 8. The coating material as claimed in claim 1, wherein thecompound (B) has a carbamate equivalent weight of from 300 to 600 g/equivalent.
 9. The coating material as claimed in claim 1, wherein theratio of hydroxyl groups to carbamate groups of the compound (B) is from1:15 to 1:0.8.
 10. The coating material as claimed in claim 1, whereinthe ratio of the hydroxyl groups of the constituents (A) and (B) to thecarbamate groups of the compound (B) is from 0:10 to 1:0.5.
 11. Thecoating material as claimed in claims 1, wherein at least 15 equivalent% of the hydroxyl groups present in the (meth)acrylate (co)polymers (A)and the compounds (B) are primary hydroxyl groups.
 12. The coatingmaterial as claimed in claims 1, wherein the crosslinking agent (C) is amelamine resin or an amino resin mixture having a melamine resin contentof at least 60% by weight, based on the amino resin mixture.
 13. Thecoating material as claimed in claim 1, wherein the variable R in thegeneral formula stands for an alkyl group having 1 to 8 carbon atomsand/or the variable X in the general formula stands for an oxygen atom.14. The coating material as claimed in claim 1, futher comprising atleast one of a crosslinking agent (E) other than (C) and (D), anadditive (F) and a pigment (G).
 15. The coating material as claimed inclaim 1, which after it has cured has a storage modulus E′ of at least5*10⁷ Pa.
 16. A process for preparing a coating material as claimed inclaim 1, in which (A) at least one hydroxyl-containing (meth)acrylate(co)polymer, (B) at least one compound containing carbamate groups andhydroxyl groups, (C) at least one amino resin, and (D) at least onecompound of the general formula

in which the variables R and X are as defined above are mixed with oneanother and the resulting mixture is homogenized, wherein theconstituents of the coating materials are selected such that (I) atleast 10 equivalent % of the hydroxyl groups present in the(meth)acrylate (co)polymers (A) and/or the compounds (B) are primaryhydroxyl groups and (II) the coating material, after it has been cured,has a storage modulus E′ in the rubber-elastic range of at least 1.5*10⁷Pa, the storage modulus E′ having been measured by dynamic mechanicalthermoanalysis on homogeneous free films with a thickness of 40±10 μm.17. A composition selected from the group consisting of coatings,adhesive films, seals, moldings and self-supporting films comprising thecoating material of claim
 1. 18. Coatings as claimed in claim 17,comprising one of a clearcoat and a pigmented paint systems.
 19. Acoating as claimed in claim 18, comprising a multicoat paint system. 20.Coatings as claimed in claim 19, wherein the coatings are clearcoats ofmulticoat paint systems.
 21. A coating as claimed in claim 17, whereinthe coatings exhibits a gloss difference in the AMTEC test of less than35 units.